288 
Mycologia 
with conspicuous, glabrous zones of various colors, mostly later- 
iceous, bay or black ; margin thin, sterile, entire ; context thin, 
membranous, fibrous, white ; tubes punctiform, less than i mm. 
long, white to isabelline within, mouths circular to angular, regular, 
even, 4-5 to a mm., edges thick and entire, becoming thin and 
dentate, white, glistening, at length opaque-isabelline or slightly 
umbrinous ; spores allantoid, smooth, hyaline, 4-6 X 1-2 /t. 
Abundant everywhere on dead wood, both in temperate and 
tropical regions, causing decay in tree trunks and often producing 
root-rot in trees when they are weakened by lack of food or other 
unfavorable conditions. The photograph is from a young black 
birch attacked by the fungus. 
Coriolus prolificans (Fries) Murrill 
Lacerate Coriolus 
Plate 103 
Pileus exceedingly variable, sessile or affixed by a short tubercle, 
dimidiate to flabelliform, broadly or narrowly attached, 2-5 X 2-6 
X 0.1-0.3 cm.; surface finely villose-tomentose, smooth, white or 
slightly yellowish, marked with a few narrow, indistinct, latericeous 
or bay zones ; margin thin, sterile, entire to lobed ; context very 
thin, white, fibrous ; tubes 1-3 mm. long, white to discolored within, 
mouths angular, somewhat irregular, 3-4 to a mm., usually becom- 
ing irpiciform at an early stage, edges acute, dentate, becoming 
lacerate, white to yellowish or umbrinous ; spores smooth, hyaline. 
Exceedingly abundant at times on dead deciduous trunks from 
Canada to Florida and west to Wisconsin and Mexico. I have 
seen oak trunks nearly a hundred feet long entirely covered with 
the fruit-bodies of this species. The walls of the tubes usually 
split at an early stage, causing beginners to mistake it for an Irpex 
or a Hydnum. 
Irpiciporus mollis (Berk. & Curt.) Murrill 
Soft Irpiciporus 
Plate 104 
Pileus sessile, dimidiate, imbricate, decurrent, 3-4 X 4“^ X 1-3 
cm. ; surface white, finely pubescent, azonate, sulcate at times. 
